- #1
androbada525
- 13
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A 60W,220V bulb and a 40W,220V bulb are connected in series to a supply of 220V. Find the resistance of each bulb and the current flowing through each bulb.
My Solution:
I took the current to be same as the bulbs are connected in series.
As the current will be the same in each bulb, I took the current as 'i'
P=V*i
For bulb with power 60W
60=v*i
v=60/i
For bulb with power 40W
40=V*i
V=40/i
Adding V and v
V+v=220
40/i + 60/i = 220
100/i = 220
i = 100/220 = 10/22 = 5/11
Then I calculated the resistance by using the formula P=i^2 * r
Have I done the question correctly?
If no, then please point out the mistake
My Solution:
I took the current to be same as the bulbs are connected in series.
As the current will be the same in each bulb, I took the current as 'i'
P=V*i
For bulb with power 60W
60=v*i
v=60/i
For bulb with power 40W
40=V*i
V=40/i
Adding V and v
V+v=220
40/i + 60/i = 220
100/i = 220
i = 100/220 = 10/22 = 5/11
Then I calculated the resistance by using the formula P=i^2 * r
Have I done the question correctly?
If no, then please point out the mistake